Problems connecting Macs to PCs

Hello,
For the past few years we have 2 Macs (a G3 and a G4) connected to our office network (A Windows network) without having any problem.
Few days ago we were unable to connect from the Macs to the PCs..we tried to connected from both macs using AppleTalk without any success..
No1 touched the Macs, and the only thing that could be changed is something on the router (I doubt it but i dont have a clue in those areas).
We have Doubletalk on the G4 installed, and withit we can connect. But the G3 is still not connected and we dont have a clue why...
Now we asked our Tech guys but all they know is about Microsoft servers...so they can't help us.
My questions are: What did they change that could cause the AppleTalk not to work but doesnt affect the DoubleTalk?
and How do I fix that?
Thanks in advance,
Oracio

It's always possible that the tech team accidentally blocked the port that AppleTalk is talking (for lack of a better word) on – maybe at the router or with another firewall. They maybe also have installed something on the server thats interfering .

I'd check with them what they've done over the last few days and tell em to change it back .

Are you running OS X or Classic on the two systems?

Mark.

i dont know windows well, but i know that in some versions of the server, you can make it so macs are not allowed to connect. check on that.

also check the ports on the router and look at the allowed ports for the server, as mentioned above. ^

ryan